Paver Calculator
Enter the patio or path size in metres to get the number of pavers, tonnes of MOT Type 1 sub-base, sharp sand and an estimated cost in GBP.
Formulas shown on this page · Last reviewed October 2026
Tonnes assume the thickness you enter is the compacted depth, using about 2.1 t/m³ for the base and 1.6 t/m³ for sand. Suppliers’ densities vary, so confirm with your merchant.
How the paver calculator works
pavers = area ÷ ((width + joint) × (length + joint)) × (1 + waste)
tonnes = area (m²) × depth (mm) ÷ 1,000 × density (t/m³)
Choose a common size for the UK – the presets cover the sizes most often sold as paving slabs and block paving at builders’ merchants and paving suppliers – or enter a custom size. Joint width is added to each unit, and about 10% extra covers cuts and breakages.
Base and bedding layers
MOT Type 1 is the standard sub-base, usually 100–150 mm compacted with a plate compactor; use the deeper end for driveways. The calculator uses 100 mm of MOT Type 1 sub-base and 30 mm of sharp sand by default; both depths are editable.
| Layer | Default depth | Density used |
|---|---|---|
| MOT Type 1 sub-base | 100 mm (compacted) | 2.1 t/m³ |
| sharp sand | 30 mm | 1.6 t/m³ |
Depths are treated as the finished, compacted thickness, so the density is that of compacted material. Loose material is lighter per cubic metre but compacts down by around a fifth, so both approaches give a similar tonnage to order. An extra 10% allows for uneven ground and spillage.
Slabs are normally laid on a bed of sharp sand (or a mortar bed), while block paving sits on 30–50 mm of sharp sand and is edge-restrained. Prices are typical – check local prices and enter your merchant’s per-tonne rates; delivery is not included.
Frequently asked questions
How many 600 × 600 mm pavers for a 5 × 4 m area?
The area is 20 m². With 5 mm joints and 10% waste you need 61 pavers.
How much MOT Type 1 sub-base do I need for 20 m²?
At 100 mm compacted and 2.1 t/m³ that is 4.2 tonnes, or about 4.6 tonnes with 10% extra.
How much sharp sand is needed?
A 30 mm bed over 20 m² is 0.6 m³, about 1.06 tonnes at 1.6 t/m³ with 10% extra – roughly 43 bags of 25 kg.
What will the project cost?
At the default prices the pavers, base and sand for 20 m² come to about £912, excluding edging, delivery, labour and plate-compactor hire.